In a first step we apply the Everest pipeline by [1]}, [2]} on our sample of 135 pre-MS stars to remove instrumental noise. The oscillation frequencies of optically visible pre-MS solar like oscillators are expected to be above \({100}{\mu Hz}\)  (see Fig. REF ). Thus, we can safely filter out the frequencies in the lower frequency ranges that are caused by interactions between the star and its surrounding disk as well as activity in the star. This is also necessary, as the amplitude of these low frequency variations are significantly higher than the expected amplitude of the oscillations. Not removing these variations would make it impossible to detect potential oscillations in our sample. We therefore apply a Savitzky-Golay (Savgol) filter [3]} and choose a third-order polynomial with a window size between 41 and 331, depending on the individual data set.
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